It's very possible that you have a leak (pinhole, even) in one of the
front rigid lines or flex hoses. Perhaps this is why the PO redid the
calipers..not realizing that the brake problem is in the lines.
Pinholes will not leak much fluid, but will suck air back in the
system.
If you have flex lines, sometimes the inside of the those hoses
disintegrates, with a flap hanging down, which impedes the flow of
brake fluid.
If you are getting a firm pedal and brake action on the rears, most
likely the MC is fine. Generally if you press on the brake pedal, and
you feel the pedal then continue to slowly sink to the floor, that's
an MC that needs replacing.
At this age, I usually buy a new or professionally rebuilt unit. (Just
got one, a Beck Arnley unit through NAPA for $119 and it came with a 1
yr. warranty.) By the time you add up re-sleeving and the rebuild kit,
a rebuilt one is not much more.
How many times did you do the "open....close" cycle? Remember, the
pedal must be held completely down until the bleed screw is tightened.
If the pedal is let up and the bleed screw was opened, even a little,
that would suck air in, if the bleed screw tubing was not submerged in
fluid.
Hope this helps....
Valerie Stabenow,1962 mga,1967 tr4a, 1969 xk-e, 1973 tr6, 1981
corvette
----- Original Message -----
From: "Dwayne Cooper" <dcooper@paciolan.com>
To: "6pack (E-mail)" <6pack@autox.team.net>
Sent: Thursday, August 09, 2001 7:47 PM
Subject: Master Cylinder problem?
> I finally put the front calipers, rebuilt by the dpo, on my '73 over
the
> weekend. I didn't have a problem bleeding the back brakes, but
can't
> seem to get the air out of the front brakes. No matter how much I
pump,
> I still get air. After wearing out my wife and son, I went to the
local
> auto parts store and bought a vacuum bleeding gizmo, but still no
joy.
>
> Does this mean my Master Cylinder needs rebuilding? What I find
most
> puzzling is trying to figure out where the air could be coming
from...
> It appears to be a closed system, if the Master Cylinder weren't
> working, I'd expect no fluid or bubbles to come through the system.
> What I'm getting is some fluid and a steady stream of bubbles.
>
> Any help would be much appreciated.
> ________________________
>
> Dwayne Cooper
> Product Manager
> Paciolan
> dcooper@paciolan.com
> Phone: 949/476-1212
> Fax: 949/475-1199
|